In the quivering heat of the Cuban noon, a mournful sound rose up over the aluminium rooftops of Camp Delta. It was the Muslim call to prayer.

Thousands of miles from home, America's prisoners in the War on Terror were kneeling towards Mecca, and probably praying for release.

Journalists are not allowed anywhere near the prisoners

Not that we could see them. The new camp, completed in April, is very different from the see-through cages of Camp X-ray. The shackles, the hospital trolleys, the orange boiler suits, are now all out of sight.

They are hidden behind closed walls, ringed by coils and coils of razor wire and watched by armed guards in their observation towers.

Close to 600 prisoners from nearly 40 countries are here now.

As I was driven round the perimeter, I saw teams of Indian labourers building yet more security fences. Work has begun on an extension: 200 more cells are being built. The place feels like a construction site.

No access to prisoners

For reasons of what the Americans call "operational security", the media are not allowed anywhere near the prisoners.

Just getting here takes days. It is a wearying process of night-time transfers through US naval airbases, bag searches, sniffer dogs and rules and regulations barked out by huge men in baggy camouflage.

But, of course, it is nothing compared to what the prisoners themselves experience. Standing on the scorching tarmac at Guantanamo airfield, the sweat trickling down the back of my neck, I tried to put myself in their shoes.

The ready smile on his tanned face turned to a grimace as he told me how some had tried to smash their heads against the walls or slash their wrists with plastic cutlery

Within the space of days you have been whisked from Central Asia to this Caribbean outpost. Dazed and disorientated after a 20-hour flight, your hands are manacled, your ears are muffled.

Your mouth is covered by a mask to prevent the spread of tuberculosis.

Now you are being herded into a shed by people you think want to kill you. Will you be tortured? Will you be forced to renounce your religion? Will you ever be set free?

Treatment

But in reality, the US authorities have gone to some lengths to provide what they see as humane treatment for their captives.

In Camp Delta, I was told, they are being housed in individual cells measuring eight feet (2.4 metres) by six and a half feet (1.9 metres.

Each inmate gets a window, running water, and a bed marked with the direction of Mecca.

Prisoners have no access to their family or lawyers

There is a library stocked full of Korans and the prisoners can write up to six letters home a month. They are being examined by medics, and visited by the Red Cross.

But what they are not getting is access to lawyers, nor to their families.

The US classes them as simply "detainees", not even as prisoners of war.

The psychological strain must be enormous. Beneath the shiny mesh of the prison fence I met Commander Radke, a US Navy medic who has been examining some of the prisoners.

The ready smile on his tanned face turned to a grimace as he told me how some had tried to smash their heads against the walls or slash their wrists with plastic cutlery.

Most were co-operative but some had thrown their own urine at guards. Several had tried to commit suicide, he said. They were unsuccessful.

The camp's chaplain spoke of certain prisoners being what he called "possessed by evil", devoid of any remorse for the events of 11 September.

A medical team looks after the detainees

They were not, he admitted, the kind of men he would like to introduce to his mother. But, after a while, he said, they had mellowed.

He was probably the first Christian many of them had met and he hoped they had come to realise that he was not the devil incarnate.

On the other side of the camp, I tracked down the man in charge of interrogating the prisoners.

In the shade of a fruit tree, Colonel Dennis Fink spoke of the slow, methodical pace of the interrogations.

No physical contact is allowed between detainee and interrogator, he said. After some of the treatment these people have received from their own security services that must come as a huge relief.

But it also begs the question: What is America getting out of Guantanamo Bay?

Whatever information they can coax out of the detainees is now months out of date.

Most of the men here played very minor parts in al-Qaeda or the Taleban. Some quite possibly played none at all.

The few big names they have caught are unlikely to be telling the truth.

Waiting game

My Saudi sources tell me that long before 11 September they had been trained in ways to resist and deceive interrogators.

But, when it comes to Guantanamo Bay, America's patience seems to be endless.

After my visit to this prison camp I am getting the strong impression that the US is in no hurry to release, or even to try these men.

One day it will have to. But as long as Washington fears another attack by al-Qaeda, it will keep these men here as long as it can.